Chiari III malformation with proatlas abnormality.

Chiari III malformations are extremely rare hindbrain malformations that are associated with a high early mortality rate, or severe neurologic deficits in the survivors. They are characterized by an occipital or cervical encephalocele, along with anomalies commonly seen with the type II malformation. Chiari III in association with proatlas abnormality is very rare. Here we describe a patient with Chiari III malformation associated with occipital condyle hypoplasia.